1. Field of the Invention
The present invention relates to a spindle motor and a disk drive apparatus.
2. Description of the Related Art
A hard disk device or an optical disk device is equipped with a spindle motor for rotating a disk. The spindle motor includes a stationary unit fixed to a housing of a device and a rotary unit rotating together with a disk supported thereon. In the spindle motor, torque acting about a center axis is generated by magnetic flux generated between the stationary unit and the rotary unit, whereby the rotary unit is rotated with respect to the stationary unit.
A conventional spindle motor is disclosed in, e.g., Japanese Patent Application Publication No. 2011-114892. The spindle motor of Japanese Patent Application Publication No. 2011-114892 includes a base member, coils, and a circuit substrate. Lead wires extending from the coils are led out via through-holes of the base member and are connected to the circuit substrate.
In this spindle motor, there is a need to electrically insulate the lead wires led out from the coils from the base member. Particularly, the spindle motor is becoming thinner and thinner in recent years. Consequently, the diameter of the lead wires making up the coils tends to become smaller. If the diameter of the lead wires becomes smaller, the protection film covering each of the lead wires grows thinner. For that reason, if the lead wires having a small diameter contact the base member, there is a fear that the lead wires may be damaged by even light contact. Thus, it is desirable to prevent the lead wires and the base member from contacting each other even under a tension state.
As the spindle motor becomes thinner, the base member also becomes thinner such that the rigidity of the base member is decreased. In order to maintain the rigidity of the base member, there is a need to reduce the size of a base through-hole. Accordingly, it is preferred that the base through-hole be shaped to easily lead out the lead wires therethrough.